not one, but several science stories. Tonight, they're basically puzzles beginning with a

problem, so just...

Come on back. Come on back and...all right, stop. Good. The internal combustion engine,

which fouls the air and uses gas which comes from oilówhich is getting expensive, involves

the Middle East, gets us into all kinds of fightsówho wouldn't want to replace this

with a more efficient and affordable alternative?

But is there an alternative?

Well, there is this engine we keep hearing about which is supposed to be fabulous. It's

coming "soon." But the puzzle is, how soon?

Every year, Detroit unveils, with much to do, a "Car of the Future." And the hoopla

here isn't about what this car does. It's about what this car doesn't do. This car doesn't

use gasoline, none, because it is powered by a fuel cell.

GEORGE W. BUSH (President of the United States, 2001- ): Fuel cells...

NEWS ANCHOR : ...fuel cells.

NEWS CORRESPONDENT: ...powered by a fuel cell.

GEORGE W. BUSH: Fuel cells are the wave of the future.

NEWS CORRESPONDENT:The wave of the future.

ROBERT KRULWICH: Really? This is the future? Well maybe we should take a closer look.

So I decided to test drive a fuel-cell car, and I invited a couple of friends to come

along.

What do we think?

TOM MAGLIOZZI: We don't know anything.

ROBERT KRULWICH: Tom and Ray Magliozzi, the Car Talk guys from National Public Radio.

RAY MAGLIOZZI: What was that whistling noise?

ROBERT KRULWICH: Yeah, what is that whistling?

RAY MAGLIOZZI: What's that about?

ROBERT KRULWICH: Mmmmmm.

TOM MAGLIOZZI: That sounds like F above middle C. I would like to open the hood just to see

what's there. Don't shut it off.

RAY MAGLIOZZI: And don't lock the keys in it. I'll leave a window open. I'm dying to

see what's under here.

TOM MAGLIOZZI: What the heck is this? See, I knew it. It's not an engine!

ROBERT KRULWICH: Well, it has a box, and it has lots of things connecting to it.

RAY MAGLIOZZI: Yeah, my intuition tells me this is an electric motor.

TOM MAGLIOZZI: This is basically an electric car.

RAY MAGLIOZZI: You know what it sounds like? It sounds like my Norge refrigerator used

to sound.

ROBERT KRULWICH: Tom and Ray know a lot about regular cars, the ones with internal combustion

engines.

This, on the other hand, is an electric car. But you don't plug it in, instead, it's powered

by this mysterious fuel cell thing.

RAY MAGLIOZZI: This is stuff, this is technology that none of us understands.

TOM MAGLIOZZI: No one told us this.

RAY MAGLIOZZI: Do we need help? We need help.

ROBERT KRULWICH: Maybe we should ask...

RAY MAGLIOZZI: We need someone, a passerby, just some ordinary citizen.

ROBERT KRULWICH: Dan.

TOM MAGLIOZZI: Who?

ROBERT KRULWICH: Oh, my god. Thank goodness the car comes with its own expert, Dan Kelly,

who works for a company that actually makes fuel cells.

RAY MAGLIOZZI: So it has an electric motor. What runs the motor?

DAN KELLY: All the electricity comes from the fuel cell. And the fuel cell is really

made up of a collection of these.

ROBERT KRULWICH: This is a fuel cell? It looks like a black plastic license plate.

DAN KELLY: This is one cell. And it's like a sandwich; you just stack them up. You want

more power, add more cells. Make a bigger sandwich. And what goes through, if you look

at it...

RAY MAGLIOZZI: It's a piece of plastic!

DAN KELLY: ...and the grooves that are in it...

ROBERT KRULWICH: Yeah, what is this?

DAN KELLY: ...you get...Hydrogen runs through these grooves.

ROBERT KRULWICH: So what's really going on inside these little holes? How is this thing

making electricity?

Well, inside the fuel cell, there are two sets of tiny passageways separated by a membrane.

And if you look very close, the two main sections are kind of like the two sides of a tennis

court. On one side is hydrogen and on the other side oxygen, and then there's the membrane

that separates them. It's kind of like a net.

So here we are in a tennis court. I, of course, you'll notice now, represent the atom oxygen,

and for those of you who are oxygen atoms yourselves, you'll, of course, recognize that

I have eight electrons. This is a fuel cell, so oxygen is opposite hydrogen. There are

two hydrogen atoms, and if you'll rotate please, you'll see that they too each have one electron.

Now it is in the nature of this kind of chemistry that hydrogen and oxygen are attracted to

each other.

RAY MAGLIOZZI: I yearn for you, Robert.

ROBERT KRULWICH: You yearn for me, but there is a membrane between us. Now the rules of

the fuel cell are you will try to come to meótry to come to meóbut you'll have to

go under or through the membrane. Try under the membrane.

TOM MAGLIOZZI: Try under. Okay.

ROBERT KRULWICH: Down they go, the two hydrogen atoms approaching the oxygen with ardor, but

notice now...

TOM MAGLIOZZI: We can do it! Robert, I love you!

ROBERT KRULWICH: ...through the membrane...

TOM MAGLIOZZI: We made it, Robert! We made it! Oh, my god, finally.

ROBERT KRULWICH: Now, butóand I use the word "but" advisedlyócould you please rotate?

So show the audience your butts at this moment. You'll notice that this has got no electron;

no electron here. The question has to be asked, "Where are the electrons?"

Remember when the hydrogen had to come through the membrane? Well, when it did that, its

electrons were stripped off. Electrons simply aren't allowed through the membrane in a fuel

cell.

But they do want to come to the other side. So very cleverly, they go around the membrane,

right at the edge of the fuel cell, over and over and over again. And moving electrons,

well, that's electrical current. That's what lights up a light bulb, or, in this case,

what powers your car.

And here's what makes the fuel cells so clean: after the electrons get to the other side,

they rejoin their old friends, hook up with the oxygen, and before you know it, you've

got H2Oówaterópretty neat.

So in these cars, when you check the tailpipe, instead of exhaust, what you get...

RAY MAGLIOZZI: ...is water.

ROBERT KRULWICH: Oh, how do you know?

RAY MAGLIOZZI: 'Cause it looks like water.

TOM MAGLIOZZI: Take a drink. Lick it. Lick it!

He's dead! I didn't like him anyway.

ROBERT KRULWICH: The very idea that a car's motor could be this clean has an enormous

appeal, especially to certain politicians. They act like it's going to be easyówell,

sometimes they doóbut as it turns out, there's a catch, actually, a bunch of catches. Fuel

cells are still very expensive to make, they wear out more quickly. And, oh, yeah, there's

another thing...

DANIEL NOCERA (Massachusetts Institute of Technology): A fuel cell needs fuel, so we've

been talking about hydrogen and oxygen as our fuel. There's lots of oxygen. But where

are we going to get the hydrogen in the first place?

ROBERT KRULWICH: MIT chemistry professor, Dan Nocera, says, "Remember, you've got to

have pure hydrogen, all by itself, on one side of the membrane to get things going."

So where do you get pure hydrogen? Well, there's plenty of hydrogen on earth; it's just not

pure. It's stuck to other stuff, like oxygen, in water, of course. And hydrogen can be found

in fuels like natural gas, you know, hydrocarbons.

But if you take it out of thereóand that's where most hydrogen comes from todayóyou

do get a waste product, carbon dioxide. And that's one of the bad guys in global warming.

So what's the answer?

DANIEL NOCERA: I think water is the key for the future.

ROBERT KRULWICH: Every high school chemistry student knows how to split water into hydrogen

and oxygen. You just run electricity through it. That's electrolysis.

But hydrogen and oxygen are so cozy and comfortable together, you use up so much electricity prying

them apart, it could cost a fortune. So we are facing a significant technical problem

here: how do we find a cheap, clean source of hydrogen?

Oh, and there is another issue...

RAY MAGLIOZZI: Excuse us for a minute.

TOM MAGLIOZZI: We'll be right back.

ROBERT KRULWICH: Yeah. Don't we worry a little bit about the danger problem?

RAY MAGLIOZZI: What about the Hindenburg?

ROBERT KRULWICH: Yeah, what about the Hinden...the huge balloon the Germans...

RAY MAGLIOZZI: Yeah. Oh, the humanity...the whole thing.

TOM MAGLIOZZI: We've got to ask him.

RAY MAGLIOZZI: Yeah, Come on.

TOM MAGLIOZZI: Dan...

RAY MAGLIOZZI: What about the Hindenburg? Remember the Hindenburg?

TOM MAGLIOZZI: Yeah, what about the Hindenburg? Yeah.

DAN KELLY: The Hindenburg?

ROBERT KRULWICH: The Hindenburg pretty much ruined hydrogen's reputation. But after the

explosion, the fire here, the continuous flames that you see, some say they came from the

canvas blimp which was coated with highly flammable shellac.

DAN KELLY: Are you comfortable getting back in now?

RAY MAGLIOZZI: Not really, no. I'll be walking back.

ROBERT KRULWICH: One moment, one moment.

Of course, gasoline is flammable, too, and we drive around with gallons of that in our

cars.

It's something else about hydrogen...

NATHAN LEWIS (California Institute of Technology): Well, hydrogen's a gas.

ROBERT KRULWICH: Okay, so?

NATHAN LEWIS: That means most of the space between the hydrogen molecules is not useful

to make energy. There's nothing there.

ROBERT KRULWICH: So says Nate Lewis, a scientist at Caltech.

Getting enough hydrogen into a car is a challenge, because it likes to spread out, and you've

got to squeeze a lot of it into a small place.

You can't use an ordinary gas tank to hold it, because it would burst open. And you wouldn't

want that.

Did I run a stop sign?

RAY MAGLIOZZI: Noooooooo.

ROBERT KRULWICH: No? All right.

So the hydrogen tanks have to be super strong, to hold hydrogen squeezed in at pressures

up to five to ten thousand pounds per square inch. But even with that special tank, it's

tough to get enough hydrogen in the car. For instance, to drive 300 miles, you might need

a gas tank four times the size of the one you've got now.

Which leads Professor Lewis to suggest the best place for hydrogen fuel might be in power

stations, to light up cities and factories.

After all,